The term "demons" was not always understood
to have the absolutely negative connotation that it does today. Homer used the terms "demons" and "gods" more or less
interchangeably. Another opinion was that demons were intermediaries between men and gods, and that demons had once
been men. Plutarch speaks of "human souls as commencing, first heroes, then demons, and afterward as advancing to a
more sublime degree." Philo of Byblus seems to draw on this same tradition when he states that, "The most ancient
of the barbarians, especially the Phoenicians and Egyptians, from whom other people derived this custom, accounted those the greatest gods who had found out things most necessary and useful in life -- and had been benefactors to mankind."

Our current use of the term "demon" is to denote
a malignant spirit, and comes to us primarily form New Testament writers. However, there is still uncertainty as to
whether or not demons are considered to be distinct and separate from the Devil and his fallen angels.

Demon possession - that is, a human who
has become inhabited or "taken over" by a demon and who cannot, consequently, exercise his own will - is noted
in the New Testament, specifically in Mark, Chapter 5, ver. 12. Josephus also mentions a method of exorcism prescribed
by Solomon, which had "prevailed or succeeded greatly among them down to the present time." Unfortunately, Josephus
does not describe the method used.

There is little doubt that most of what
was described in older times as "demon possession" would today be diagnosed as some sort of mental illness, and treated accordingly.
Nevertheless, a few cases of possession do seem to crop up from time to time, and the Roman Catholic Church does continue
(sparingly) to perform exorcisms.

Ancients also had a sort of faith in the prophetic
words spoken by those whom they believed to be possessed by demons, and this was sometimes a component of ancient oracles.
In connection with this, it is worth pointing out that a respected modern-day professor of psychology once witnessed a friend,
who was suffering from paranoid schizophrenia make a specific and surprising prophecy that turned out to be perfectly accurate.
The professor had no explanation for this event. although one is tempted to hypothesize that there is a link between altered
mental states and psychic ability. Some also associate the ouija board with demoniacal prophesy, and those who have seen Linda Blair in The Exorcist will recall that
this was how her character's problems began.

Some historians of times past believed that there were cycles during which demonic activity increased, and used this theory
to explain various occurrences, much in the same way as today's economic historians might explain historical events in terms
of trade, productivity and other factors. These older historians saw a rise in demonic activity accompanying such occurrences
as the destruction of Jerusalem, the fall of Rome and the French Revolution, and would in all likelihood also have viewed
the demonic theory at work in relation to the rise of Nazism and World War II.